Insulated door and mounting structures therefor



Oct. 1, 1957 F. w. KNOWLES 2,807,836

INSULATED DOOR AND MOUNTING STRUCTURES THEREFQR Filed July 6, 1954 3 Sheets-Shet l INVENTOR.

A FRANK I44 KNOW/L55 A r roe/v96 Oct. 1, 1957 F. w. KNOWLES 2,807,336

INSULATED DOOR AND MOUNTING STRUCTURES THEREFOR Filed July 6, 1954 3 Sheets-Sheet 2 LZ y 6'.

INVENTOR. FRANK n4 KNOW/L66 I WM: mm 6,|/- A TTOE/VEVS v1957 F. w. KNOWLES INSULATED DOOR AND MOUNTING STRUCTURES THEREFOR Filed July 6. 1954 3 Shuts-Sheet 5 INVENTOR. FRANK W KNOWL E5 aten't fiFice 2,897,835 Patented Oct. 1, 1957 INSULATED DOOR AND MGUNTIN STRUCTURES THEREFOR Application July 6, 1954, Serial No. 441,435

7 Claims. (Cl. 20-25) The door of the present invention is intended primarily for use as a closure for refrigerators, cold storage rooms and the like. Consequently, such doors must be insulated effectively to deter transfer of heat from them, and they must be sealed tightly when closed. Because of their insulation requirements such doors are heavy and awkard to handle, yet to be effective they must be capable of being positioned precisely.

A principal object of the present invention is to provide mounting structure for an insulated door which will enable the door to be moved relatively easily between closed and open positions and vice versa, yet when closed its edges will fit tightly about the margin of the doorway to provide an efiective seal. More specifically, it is an object to mount such a door for sliding out of and into registry with the doorway and to provide door mounting structure which will unseal the door during its first increment of movement away from closed position and which will efiect secure sealing of the door during the last increment of its movement into closed position.

In accomplishing these objects it is a further object to provide door mounting structure of rugged construction, yet which can be manipulated easily by a single person to move the door into and out of closed position. Moreover, such mounting structure is simple in nature, will not wear readily and requires a minimum of servicing to keep it in good operating condition.

Another object is.to provide a sealing structure about the margins'of thedoor and doorway which will be effective to provide a tight seal and which will not become frost-bound so that the door cannot be opened readily.

The foregoing objects can be accomplished by utilizing a door mounting track supported so that its end adjacent to the'doorway can be lifted and retracted'from the doorway simultaneously to shift the door slightly upward and outward in its initial movement from sealing position or closed position toward open position. 'The door may then be moved edgewise along the track out of registry with the doorway. In closing the door it is moved edgewise along the track into registry with the doorway, whereupon the end of the track adjacent to the doorway can be lowered and moved toward the doorway so that the door simultaneously will be droppedand moved toward the doorway so that the margins of ithe door and doorway come into sealing engagement. ,,Wedging surfaces interengageable by downward movement of the door assist in moving it toward the doorway after the door is substantially in'registrywith the doorway. Around the margin ofthe door or doorway are-arranged thermalinsulation stripsaswell as resilient sealing strips, which insulationstrips serve as '--a barrier to the transfer of"heat-at the location ofthe sealing strips' so that frost does 'notcollect at the junction'between such strips and the surface which they engage to create a frost-bound condition preventing the sealingstrips from 'beingsjeparated easily fromthe surface which they engage.

A' preferred type of door and door mounting con struction isshown in the accompanying drawings, and

its various features are pointed out in the following detailed description.

Figure 1 is a top perspective view of a door and door mounting incorporating the present invention, showing the door in closed position, and Figure 2 is an edge ele-' vation view of the door as seen from line 2-2 of Figure 1.

Figure 3 is an enlarged fragmentary edge elevation view as seen from line 3--3 of Figure 1, and Figure 4 is a fragmentary plan view viewed from line 4-4 of Figure 3.

Figure 5 is a top perspective view of a door and its mounting structure with the door in registry with its opening, but lifted and moved transversely away from the closed position of Figure 1 so that the door is unsealed. Figure 6 is an edge elevation view of the door in this position, seen from line 66 of Figure 5. v V Figure 7 is a fragmentary edge elevation view as seen from line 7 -7 in Figure 5, and Figure 8 is a'fragmentary plan view viewed from line 8-8 of Figure 7..

Figure 9 is a top perspective fragmentary view of the structure shown in Figures 7 and 8 and with the parts in the same position, a portion of the structure being brokenaway to reveal the internal construction.

Figure 10 is a fragmentary sectional view through the upper portion of the door, taken on line 1010 of Figure.8 and Figure 11 is a fragmentary sectional view through the bottom portion of the door, taken on a corresponding line. Figure 12 is a fragmentary sectional view through anedge-portion of the door takenon line 12"12 of Figure 7.

-In the wall 1 of the cold storage or refrigerated space is the door opening 2, about the outer side of which is the door casing 3. Such door casing includes an upright strip at one upright edge of the doorway, a panel at the opposite edge of the doorway and a strip across the top of the doorway. Overlying the last-mentioned strip is an angle iron 4 serving as a mounting for the overhead track 5 on which is supported the sliding door 6 adapted to close the door opening 2.

The overhead rail 5 is not supportedfixedly, but its endremote from the doorway 2 is supported for limited universal swinging movement by an upright pivot 7 carried by a bracket 8 suitably supported from the angle iron 4 and the door casing panel. Such pivot will enable the end of the track 5 adjacent to the doorway to move toward and away from the door casing, and the track fits the pivot 7 sufficiently loosely so that its end adjacent to the doorway has an appreciable, though limited, vertical movement.

The end of track 5 adjacent to the doorway is sup ported by a bearing pin 9 projecting lengthwise of the track beyond its end. This pin is journaled in the swinging end of one arm 10 of an offset-arm type of bellcrank. The other arm 11 of such bell crank, as shown in Figures 3 and 7, extends generally opposite from the 'arm 10, such as to form an angle of approximately between the arms. The journaled ends of the bell crank. arms 10 and 11 are interconnected by a short shaft 12 to which they are secured, and this shaft is journaled in the hanger 13, which is supported from the angle 4 and door casing, as shown in Figures 3 and 7. p

A second bell crank mechanism is mounted on the door casing beneath the movable end of track 5, and it includes the arm 14 mounted on a shaft 15. This shaft has one end journaled in a plate 16 secured to the door casing and its opposite end is journaled in ab'ear'ing' bracket 17 supported from the door casing. The other arm 18 of the second bell crank mechanism is secured to the outer end of the shaft 15 and may be at an angle of about 30 to the arm 14;

The-swinging end -of arm 14 is connected by a tif member, such as the rod 19, to the swinging end of the arm 11 of the upper bell crank mechanism. The arm 18 may constitute a track shifting lever which has a handle on its swinging end. Swinging of such handle will shift the movable end of track 5. In order for the end of the track 5 to be shifted from the position shown in Figures 1, 2, 3 and 4 to the position shown in Figures 5, 6, 7 and 8, the shaft 12 of the upper bell crank mechanism must turn through slightly less than ninety degrees. The length of arms 11 and 14 will be selected so that the operating handle arm 18 must swing through approximately this same angle to effect such movement of the track end.

The door 6 is supported by hangers 20 and 21 secured to its upper edge at spaced locations. Each of these hangers is suspended from a carriage 22 which is received within and rolls along the track 5. An appropriate type of carriage structure for this purpose is shown in Figure 9. When the tracks movable end has been lifted and withdrawn from the door casing, the door may he slid edgewise out of registry with the doorway 2 into a position overlapping the panel which is flush with the door casing. Such opening movement of the door is limited by engagement of a door edge with an angle stop bumper ,2 mounted on such panel, and as the door is moved closed it is stopped in a position registering with the doorway by engagement of its opposite edge with a similar angle stop bumper 2" adjacent to the door opening. In a door for a refrigerator or cold storage room it is important that the door be sealed tightly about its edges when in closed position, yet it is desirable that the door be capable of being moved freely out of registry with the doorway when it is desired to open the door. Such an operation has been difficult to accomplish heretofore with a sliding type of door. On the other hand, a swinging door is quite heavy and presents a problem to support it for swinging about a vertical hinge axis. Such a swinging door also requires considerable space in which to swing it. By providing a shiftable track of the type described above in conjunction with suitable sealing and wedging mechanism, the door can be sealed effectively when closed, yet released readily for easy opening movement.

In Figures 10, 11 and 12 sealing mechanism is shown which has been found to be satisfactory for this purpose. The door 6 may be of any suitable construction having interior insulation 23. A ribbed yieldable sealing strip 24 preferably of soft rubber and having several ribs is interposed between the adjacent surfaces of the door and doorway. In the illustration of Figures and 12 this sealing strip material is shown as being mounted on the face of the door disposed next to the door casing, so that along the upright sides of the door and across the top the sealing strip material will abut the door casing. Alternatively such sealing strip material could be mounted on the door casing itself with the ribs outward. A Along the bottom of the door, as shown in Figure 11, sealing strips 25 are provided secured to the door bottom, although these strips instead could be secured to the floor, beneath the door when in closed position. While several strips 25 are shown, such sealing strip material could be of the multiple-rib type such as the strips 24 shown in Figures 10 and 12. It will be evident that lowering movement of the door will effect sealing engagement of the strips 25. Like the strips 24, these should be of soft rubber material.

- It has been found that despite tight sealing engagement of the seals 24 and 25 between the door and the doorway, frost frequently tends to form at the location of the sealing strip so that the door edges become frostbound to the doorway, maldng it ditficult to free the door from the doorway. Provision of a strip of thermal insulating material, such as cork 26 around the door embedded in the door edge and having a band of it exposed has been found to prevent such a thermal drop across the door edge as to cause frost to be produced. While in the two upright edges and the top edge of the door such thermal insulating strip 26 has been placed to have a band exposed outwardly of the rubber sealing strip, location of the thermal insulating strip to have a band exposed inwardly of the sealing strips at the bottom of the door has been found to be effective.

It will be evident that as the handle arm 13 is moved from the position shown in Figures 5 and 6 to that shown in Figures 1 and 2, the arm supporting the movable end of the track 5 will be shifted from the position shown in Figures 7 and 8 to the position shown in Figures 3 and 4. The swinging end of such arm will thus move pin 9, and consequently the end of the track which it supports, toward the doorway and downward. Since the door 6 is supported directly by such track through the hangers 20 and 21, such lowering and inward movement of the movable track end will enable the door 6 to execute a similar movement if it is disposed at the movable end of the track in registry with the doorway 2.

Because the door is heavy it necessarily will move downward conjointly with lowering of the movable end of the track, so that the sealing strips 25 shown in Figure 11 will abut firmly against the lloor when the tracl; moving handle is swung from the position shown in Figures 5 and 6 to that shown in Figures 1 and 2. Because the movement of the track follows the arcuate path traced by the pin 9, such track will move first toward the doorway and then downward during travel of the movable end of the track from the positionshown in Figures 7 and 8 to the position shown in Figures 3 and 4. As the door settles, however, both its inertia and any friction between the sealing strips 25 and the floor as they touch would tend to prevent the bottom of the door from moving tightly against the doorway margin. Consequently, wedging mechanism may be provided to insure that the bottom of the door will move toward the doorway into firm contact with it as the door moves downward.

In Figures 1 and 5 wedging cleats 27 are shown mounted on the outer face of the door. adjacent to its opposite upright edgm. These cleats are engageable with wedging bearing elements 28 anchored to the floor at opposite sides of the doorway and spaced from the doorway a distance slightly greater than the thickness of the door. When the movable end of track 5 is in its upper and outer position, the cleats 27 are raised out of engagement with the bearing elements 28, as shown best in Figure 6, and the door hangs free. As the door is lowered, however, the interengageable wedging surfaces of the cleats 27 and bearing elements 28 engage and the cleats slide down such bearing surfaces as the door is lowered until they reach the relationship shown best in Figure 2. The wedging elements will be proportioned so that when the door has been lowered completely such wedging elements will have forced the door transversely of its plane toward the door opening to press the sealing strips 24 along the upright edges of the door near the bottom firmly against the doorway. Consequently, a tight seal will be effected by the sealing strips about the entire periphery of the door.

As the track moving handle 18 is swung downward from the position shown in Figures 1 and 2, the initial movement of the door almost directly upward will quickly relieve the wedging pressure between members 27 and 28 so as to reduce the drag of the sealing strips on the doorway, and as the arm 10 moves on into the position shown in Figures 7 and 8, the door will be withdrawn bodily from the doorway and the wedging elements will have been separated sufliciently to permit such retracting movement without cocking of the door. Upon reaching the position shown in Figures 5, 6, 7 and 8, the door will be suspended freely from the track without contact With the doorway, and consequently may then be slid easily out of position registering with the doorway into open position.

The movable end of the track is shifted only a small amount by swinging of the handle 18, but preferably the track is horizontal when the door is closed so that if it is of truly rectangular shape the bottom will be horizontal when the track is in lowered position to fit a level fioor accurately. When the movable end of the track 1s ra1sed to the position of Figure 5, therefore, the track w1ll slope downward away from the door opening and opening movement of the door will thus be facilitated. The slope will not be great enough, however, to impede appreciably sliding movement of the door toward closed position. Because the track slopes somewhat away from the door opening, however, the door will remain in open position without latching so that it can never inadvertently slide into closed position to trap someone in the refrigerator or cold storage room.

I claim as my invention:

1. An insulated door and mounting structure comprising a doorway, a door, track means extending generally horizontally alongside the upper portion of the doorway, means supporting said door from and guided by said track means for sliding movement of said door between a position in registry with the doorway and an open position out of registry with the doorway, pivot means supporting the end of said track means remote from the doorway, a pin projecting lengthwise from the end portion of said track means adjacent to the doorway, bell crank means supporting said pin and operable to swing it between upward and outward and inward and downward positions to move the end of said track means adjacent to the doorway and the door downward and toward the doorway when the door is in registry with the doorway, and wedging means adjacent to the bottom of the door interengageable by such lowering movement of the door to move the lower portion of the door toward the doorway for sealing engagement therewith. 2. An insulated door and mounting structure comprising a doorway, a door, track means extending generally horizontally alongside the upper portion of the doorway, means supporting said door from and guided by said track means for sliding movement of said door between a position in registry with the doorway and an open position out of registry with the doorway, pivot means supporting the end of said track means remote from the doorway, a pin projecting lengthwise from the end portion of said track means adjacent to the doorway, first bell crank means supporting said pin and operable to swing it between upward and outward and inward and downward positions to move the end of said track means adjacent to the doorway and the door downward and toward the doorway when the door is in registry with the doorway, second bell crank means lower than said first bell crank means mounted adjacent to an upright edge of the doorway, and means connecting said second bell crank means to said first bell crank means to efiect movement of the first bell crank means by movement of the second bell crank means.

3. An insulated door and mounting structure comprising a doorway, a door, track means extending generally horizontally alongside the upper portion of the doorway, means supporting said door from and guided by said track means for sliding movement of said door between a position in registry with the doorway and an open position out of registry with the doorway, lowering means operable after said door has been moved to a position in horizontal registry with the doorway to lower said door, and wedging means adjacent to the lower edge of said door and arranged substantially symmetrically relative to the vertical centerline of the door, interengageable by such lowering movement of the door to move its lower portion transversely of the plane of the door toward the doorway for sealing engagement therewith.

4. An insulated door and mounting structure comprising a doorway, a door, track means extending generally horizontally alongside the upper portion of the doorway, means supporting said door from and guided by said track means for sliding movement of said door between a position in registry with the doorway and an open position out of registry with the doorway, lowering means operable after said door has been moved to a position in horizontal registry with the doorway to lower said door and to move its upper portion transversely of the plane of the door toward the doorway, and wedging means including cooperating wedging members fixed to the bottom of the doorway and lower portion of said door, respectively, and arranged substantially symmetrically relative to the vertical centerline of the door, intercngageable by such lowering movement of the door to move its lower portion also transversely of the plane of the door toward the doorway for sealing engagement therewith.

5. An insulated door and mounting structure comprising a doorway, a door, track means extending generally horizontally alongside the upper portion of the doorway, means supporting said door from and guided by said track means for sliding movement of said door between a position in registry with the doorway and an open position out of registry with the doorway, pivot means supporting the end of said track means remote from the doorway, bearing means projecting from the end portion of said track means adjacent to the doorway, and means supporting said bearing means and operable to move it inward and downward from a raised and outer position to move inward and downward correspondingly the end of said track means adjacent to the doorway and to move the door supported by said track means downward and inward transversely of its plane toward the doorway.

6. An insulated door and mounting structure comprising a doorway, a door, track means extending generally horizontally alongside the upper portion of the doorway, means supporting said door from and guided by said track means for sliding movement of said door between a position in registry with the doorway and an open position out of registry with the doorway, means operable after said door has been moved to a position in horizontal registry with the doorway to move said door transversely of its plane toward the doorway, yieldable sealing strip means compressible between said door and the margin of the doorway by such movement of the door toward the doorway, and thermal insulating strip means embedded in said door and having a band thereof exposed alongside said sealing strip means.

7. The insulated door and mounting structure defined in claim 6, in which the yieldable sealing strip means are on the inner face of the upright edges and top of the door, and on the lower edge of the door compressible between such doors lower edge and the floor of the doorway by downward movement of the door, and the thermal insulating strip means is embedded in the upright edges of the door and along the top of the door and has the exposed band thereof disposed between the door edge and the adjacent sealing strip means, and the thermal insulating strip means further is embedded in the bottom edge of the door and has the exposed hand thereof disposed between the inner face of the door and the sealing strip means on the bottom of the door.

References Cited in the file of this patent UNITED STATES PATENTS 378,579 Dunham Feb. 28, 1888 475,680 Dunham May 24, 1892 689,737 Mobley Dec. 24, 1901 1,135,918 Peterson Apr. 13, 1915 1,910,822 Clarkin May 23, 1933 1,938,926 Newman Dec. 12, 1933 2,199,182 Leonard Apr. 30, 1940 2,267,279 Kuenzli Dec. 23, 1941 

